Which of the following client side java script function will be called on button click event? Three functions with same name but no. of arguments were different.

function func1(arg1) {
alert('func1 which has one arguments called!');
return false;
}
function func1(arg1, arg2) {
alert('func1 which has two arguments called!');
return false;
}
function func1(arg1, arg2, arg3) {
alert('func1 which has three arguments called!');
return false;
}